<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
       <form action="${pageContext.request.contextPath}/quick4" method="post">
           <!--表明是第几个user对象的username， age-->
           <input type="text" name="userList[0].username"><br/>
           <input type="text" name="userList[0].age"><br/>
           <input type="submit">
       </form>
</body>
</html>